How Do I View the Table Permissions of a User?

Scenario 1: Run the information_schema.table_privileges command to view the table permissions of a user. Example:

1	SELECT * FROM information_schema.table_privileges WHERE GRANTEE='user_name';

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**Table 1** table_privileges columns
Column	Data Type	Description
grantor	sql_identifier	Permission grantor
grantee	sql_identifier	Permission grantee
table_catalog	sql_identifier	Database where the table is
table_schema	sql_identifier	Schema where the table is
table_name	sql_identifier	Table name
privilege_type	character_data	Type of the granted permission. The value can be SELECT, INSERT, UPDATE, DELETE, TRUNCATE, REFERENCES, ANALYZE, VACUUM, ALTER, DROP, or TRIGGER.
is_grantable	yes_or_no	Indicates if the permission can be granted to other users. YES indicates that the permission can be granted to other users, and NO indicates that the permission cannot be granted to other users.
with_hierarchy	yes_or_no	Indicates if specific operations are allowed to be inherited at the table level. If the specific operation is SELECT, YES is displayed. Otherwise, NO is displayed.

In the preceding figure, user u2 has all permissions of table t2 in schema u2 and the SELECT permission of table t1 in schema u1.

information_schema.table_privileges can query only the permissions directly granted to the user, the has_table_privilege() function can query both directly granted permissions and indirect permissions (obtained by GRANT role to user). For example:

CREATE TABLE t1 (c1 int);
CREATE USER u1 password '********';
CREATE USER u2 password '********';
GRANT dbadmin to u2; //Indirectly grant permissions through roles.
GRANT SELECT on t1 to u1; // Directly grant the permission.

SET ROLE u1 password '********';
SELECT * FROM public.t1; // Directly grant the permission to access the table.
 c1 
----
(0 rows)

SET ROLE u2 password '********';
SELECT * FROM public.t1; // Indirectly grant the permission to access the table.
 c1 
----
(0 rows)

RESET role; //Switch back to dbadmin.
SELECT * FROM information_schema.table_privileges WHERE table_name = 't1'; // Can only view direct grants.
 grantor |  grantee   | table_catalog | table_schema | table_name | privilege_type | is_grantable | with_hierarchy
---------+------------+---------------+--------------+------------+----------------+--------------+----------------
 dbadmin | u1         | gaussdb       | public       | t1         | SELECT         | NO           | YES
(1 rows)

SELECT has_table_privilege('u2', 'public.t1', 'select'); // Can view both direct and indirect grants.
 has_table_privilege 
---------------------
 t
(1 row)

Scenario 2: To check whether a user has permissions on a table, perform the following steps:

Query the pg_class system catalog.

1	SELECT * FROM pg_class WHERE relname = 'tablename';

Check the relacl column. The command output is shown in the following figure. For details about the permission parameters, see Table 2.

rolename=xxxx/yyyy: indicates that rolename has the xxxx permission on the table and the permission is obtained from yyyy.
=xxxx/yyyy: indicates that public has the xxxx permission on the table and the permission is obtained from yyyy.

Take the following figure as an example:

joe=arwdDxtA: indicates that user joe has all permissions (ALL PRIVILEGES).

leo=arw/joe: indicates that user leo has the read, write, and modify permissions, which are granted by user joe.

Click to enlarge

**Table 2** Permissions parameters
Parameter	Description
r	SELECT (read)
w	UPDATE (write)
a	INSERT (insert)
d	DELETE
D	TRUNCATE
x	REFERENCES
t	TRIGGER
X	EXECUTE
U	USAGE
C	CREATE
c	CONNECT
T	TEMPORARY
A	ANALYZE\|ANALYSE
arwdDxtA	ALL PRIVILEGES (for tables)
*	Actions for preceding permissions

You can also use the has_table_privilege function to query user permissions on tables.
1

SELECT * FROM has_table_privilege('Username','Table_name', 'select');
For example, query whether user joe has the query permission on table t1.
1

SELECT * FROM has_table_privilege('joe','t1','select');